MUSICIANS WITH HEARING LOSS REQUIRE DUAL TRAINING



         See below an article by Dr. Katya Freire for website Audiology. "This kind of patient needs special attention, as his loss will require the fitting of two technologies: hearing aids for social life, and in-ear monitors for concerts, so that there may be a feedback of his own voice and/or instruments, based on hearing level and directed to auditory protection.” Explanations about this topic presented by Dr. Katya Freire, Managing Director of Audicare, specialized in care of musicians:.

This kind of patient needs special attention, as his loss will require the fitting of two technologies: hearing aids for social life and in-ear monitors for concerts, so that there may be a feedback of his own voice and/or instruments, based on hearing level and directed to auditory protection. Explanations about this topic presented by Dr. Katya Freire, Managing Director of Audicare, specialized in care of musicians.

The limitations that hearing aids have in processing some music sound signals may lead to dissatisfaction of common patients. However, there is a subgroup of hearing impaired patients who will be highly dissatisfied: they are the musicians, who benefit more from better central auditory processing than the average subject, suffering much more from the limitations of the hearing aids.

Brazil has many musicians (60,000 professionally active musicians, according to Associação Brasileira de Musica – Brazilian Association of Music, in 2008) and studies indicate high percentage of auditory problems caused by exposure to high intensity sounds, meaning they are candidates to hearing aid fitting. A national study published in 2010 (1) showed that 21% of the assessed sample – a group of pop rock musicians – presented hearing loss in high frequencies and, among the subjects with normal audiograms, 58% had audiometric notch in at least one of the ears.

A musician with hearing loss requires differentiated management. Moreover, he requires double management, because it includes hearing aids for social situations and monitors for live shows. “In fact, the first priority for musicians are their professional needs and hearing preservation, but in many cases the audiological assessment already shows hearing loss and indicates hearing aid fitting”, reported Katya Freire, Managing Director of Audicare, a pioneer clinic dedicated to hearing preservation of Brazilian musicians.

“Plenty of support and patience”

In a video testimonial presented by the audiologist during EIPA 2014, a musical producer and composer with moderately severe hearing loss and hearing aid user for 15 years showed the complexity of treating this group of patients with specific hearing skills, and the great demand that the professional has to face. “The main challenge is probably finding the words and the best way to translate what I am supposedly listening to. The knowledge about acoustics and compression was very useful because this shared knowledge provided me with parameters and created some references. Regardless, it is a long-lasting process, that requires support and patience to reach effective results, but the musician does not only have a hearing loss, he also has a very significant emotional loss if he cannot transmit his creativity and sensitivity through music. It takes great effort, but at the same time it is very rewarding because all achievements reached through this work, dedication and experimentation are translated into actions that can touch and impact people”, he reported.

“For musician patients, music in the hearing aid sounds weird, it seems to be electronic and robotic-like, that is, it sounds distorted. The fitted musician performs very well for speech, but not for music and, because of that, the fitting process takes time, and even after habituation, which is the time the brain takes to assimilate new information, it seems that he is never really satisfied with the result”, reported Katya Freire.

At Audicare, hearing aid fitting in new patients follows a six-session protocol – that is, it lasts a maximum of one month and a half. For musicians with hearing loss, fitting requires much more time: two, three and sometimes even four months to get the right programming that can meet their perception skills.

“These requirements result from the fact that the subject hears differently from common patients, who do not have as an effective central auditory processing as musicians do. Thus, musicians are much more sensitive to hearing aid adjustment parameters, detect minimum frequencies and intensities, such as for example 2 dB variations in 750 Hz. For that reason, it takes more time to treat them", emphasized Katya Freire. “It seems illogical to think that a patient who does not have auditory processing deficit would take longer to get fitted, but musicians are extremely demanding about what they are hearing, and hearing aids do not fully satisfy them”, she completed.

Hearing aids with higher input levels

Musicians tend to demonstrate higher satisfaction with the most recent models of premium line hearing aids that offer extended frequency range, over 8,000 Hz, even if it does not reach up to 16,000 Hz, a common frequency range in musical compositions. Some hearing aids, focusing more on the profile of musicians or music lovers, can deal with the higher level of sound input, a key point to improve the performance of hearing aids with musical signal.

Some companies offer a peak input limiting level that reaches and even overcomes 110 dB SPL, which is the main reason for a musician to be happy about his hearing aid, without detecting any distorted sound.

The adjustments in the algorithms directed to music hearing are different from those of a common patient. There are options, such as omnidirectional microphone, deactivation of noise reduction, switching off or slowing the feedback suppressor (to prevent artifacts caused by frequency cutting, such as in higher instruments – the violin, for example), and having linear frequency compression. “Thus, we can have a purer hearing aid, without algorithm cutting for non-filtered music”, Katya Freire summed up.

Hearing loss management in music professionals requires hearing aid fitting and, most of the time, adaptations during their professional practice, such as live presentations. They require an additional system, named foldback, monitor speaker or stage monitor, that enables musicians to listen to what they are playing. It used to be provided only by stage monitors, but today this control can be offered with in-ear individual monitors, which are much more efficient and provide customization of the sound feedback.

CUsing the mixing console, the technician selects which band sound sources (instruments and voice) will be transmitted by UHF (acronym for Ultra-High Frequency that determines the radiofrequency range of 300 MHz to 3 GHz) to in-ear monitors, using a body-pack transmitter. In addition to selecting the instruments, the mixing technician can control sound intensity and, for this reason, knowledge in hearing physiology is important for monitoring to be personalized to the hearing profile of each musician.

This is the second aspect of the work of audiologists with musicians and sound technicians, a specialty of Audicare. “In general, the work intends to preserve the hearing of musical professionals and, for those that already have some deficit, to compensate the affected frequencies and prevent worsening of hearing levels. A musician with hearing loss that uses an in-ear monitor without customized mixing will need to increase the general volume because he may notice something is missing. This is the real danger because the sound pressure level in the ear canal will be elevated, which may actually worsen the hearing loss", explained Katya Freire.

In-ear monitor is beneficial provided that properly usedo

“The approach is very similar to fitting a hearing aid, but things are seen from a different angle, as mixing is made in dB volts and not dB SPL. Moreover, understanding about hearing aids is key to effectively act to preserve hearing in musicians", emphasized Katya Freire. For example, when there is a lesion in the outer hair cells, that is, when non-linear compression is lost and there is no amplification of low intensity sounds and attenuation of high intensity sounds, the deficit has to be reverted using hearing aids and in-ear monitors during mixing. The in-ear monitor is very beneficial, provided that it is properly used. It should be worn binaurally, even though many musicians prefer only one monitor, because they want to hear the audience and the stage. In the chapter that Katya Freire wrote about hearing health of musicians to Tratado de Especialidades em Fonoaudiologia (2), she pointed out: “Differently from what many musicians think, unilateral use is a major risk to hearing. If the purpose is to listen to voice and/or the instruments, by using the monitor unilaterally there is a trend to increase the body-pack volume to obtain better audibility and to compensate for external noise. If volume is increased in a smaller cavity, such as the external acoustic canal, the sound pressure level (SPL) produced is much greater than on the open stage, for example. Thus, the risk to develop a hearing loss is doubled in the open ear, owing to the SPL exposure on stage of all instruments playing together, and in the ear with the monitor owing to excessive SPL.” The text also emphasized that when an in-ear monitor is used in both ears, mixing may have stereo quality, providing better conditions to hear all instruments accordingly, with 3D sensation, which does not happen monoaurally.

An additional risk of monaural use is to have the musician sing louder, which may impact his voice. Auditory monitoring is, therefore, synonym of vocal preservation as well. Another advantage of using a pair of headsets is the binaural summation, a concept that also applies to hearing aids, which provides the right conditions for the brain to integrate the collected information.

One of the characteristics of customized in-ear monitors is that they have much more extended frequency response than any hearing aid, including the latest models directed to musicians. In-ear monitors transmit sounds in the range 8 Hz to 18 Hz-20 Hz, which requires the performance of high frequency audiometry, used in cases of tinnitus or other common symptoms to subjects exposed to loud sounds.

High frequency audiometry (9kHz – 20 kHz) is complementary to conventional pure tone audiometry (250Hz – 8kHz), but it is still rarely performed by professionals in the area, impacting the work of sound technicians that focus on hearing preservation. High frequency audiometry (9kHz – 20 kHz) is complementary to conventional pure-tone audiometry (250Hz – 8kHz), but it is still rarely performed by professionals in the area, impacting the work of sound technicians that focus on hearing preservation.

References

(1) Músicos de pop-rock: avaliação da satisfação com protetores auditivos Bolzachini Santoni C,Fiorini AC, Braz. j. otorhinolaryngol. 2010, Vol. 76 Ed. 4 - Julho - Agosto - (9º), 454 a 461.

(2) Saúde Auditiva em Músicos - Freire, K. Tratado de Especialidades em Fonoaudiologia, 2014 – pgs. 994- 1003. Editora Roca

Publicado em: 2015-09-30 12:01:14